High energy target facilities have been recognized as a critical challenge in development of future particle accelerators. Specifically, beam windows and targets in accelerators are exposed to radiation with very high energy protons, posing severe requirements on the materials used in these applications. The pulsed high energy beam causes severe thermal shock in the material which can lead to fracture and fatigue failure. Additionally, radiation can cause direct damage to the material which can compromise the ability of the material to accommodate this thermal stress. The formation of transmutation products, particularly helium, which can aggregate into bubbles, can cause swelling and enable crack formation and propagation. On other hand, if the temperature is too low, radiation damage accumulates in the form of internal defects (e.g., dislocations), leading to hardening and a decreased ductility of the material.
In this project we propose to develop an experimentally validated computational framework capable of predicting radiation damage evolution in beryllium, which is a promising material for applications in the current and future particle accelerators. In particular, our proposed multi-scale model is focused on Helium bubble formation and growth as a function of irradiation temperature and on the contribution of these bubbles to swelling. In addition, we propose to carry out a series of targeted ex-situ and in-situ dual-beam experiments using low-energy protons to provide critical data for validation of the model on the effects of radiation on Helium clustering, Helium bubble distribution, and dislocation loop density/size in proton irradiated Be.